Apparatus for making bituminous emulsion



l L. -KIRSCHBRAUN APPARATUS FOR MAKING BITUMINOUS EMULSION Filed April24, 1924 Nw. 1o, 1925. 1,560,826,

. PatentedfNov. 10, v l uNiT'ED'sTATEs PATENT OFFICE.

LESTER xInscnBRAUN, or CHICAGO, ILLINOIS.

mm'rus FonMAfxING :BI'rUMINoUs ,EMULsIon Application med April l24,1924. seriai No. 708,649.

,v To all whom it mag/Pommern:

a citizen of thel United States, `residing 1nv Be it known that I,LESTER KmsoHBRAUiv,

thev city of Chicago, county of Cook, and State of Illinois, have.invented certain new and useful Improvements in Apparatus. for.

aqueousliquid with the addition of a thirdsubstance which has acharacteristic ofcausing the non-adhesive coating surrounding' each ofthe dispersed adhesive particles to more rmly envelop theadhesivebitumen or like adhesive substance dispersed through l theemulsion so that the emulsion is very resistant to pressure, dilution orany other factor commonly tending to disintegrate the envelopingnon-adhesive coatings; to provide an apparatus in which, by means of theaddition of-a 'third substance, the clusters articles surrounding the ofnon-adhesive adhesive material 1n the emulsion are caused to clingtenaciously to the adhesive substance, making the emulsion substantiallyv more permanent in its character; to provlde anl apparatus holding abulk supply of emulsion under circulation at predetermined temperature;and, in general, to provide an- -apparatus of the character lreferredto.

` f The single figure is a side view partly in section of the apparatusused for producing this emulsion.

Referring to the drawing, a jacketed container 13- surrounded by jacket2 is held in position vbeneath frame .members 3 upon which is -l'nountedan overhead motor 4.

Within the container is positioned .ajacketed v 'open ended cylinder 5supported-by suitable standards 6. C Connected tion connection shown diaammatically at- .lower bearingl y means of afric- 7 is a vertical shaft8 w 'ch `is set 1n ,.'a

9in the bottom lof the container.` On t is shaft are Propellers 410having their blades pitched. in a manner to cause a circulation of theemulsion during `the mixing operation in a .-path shown by the arrows.The container is barrel shaped to present a smooth surface, and 4a shapewhich will offer the least lfrictional resist` ance to the substancescirculated therein.'

Into the outer jacketed portion may be introduced steam'or water throughthe inlet pipe 11 controlled by the' valve 12 and after circulationabout the jacketed portion 2, the circulating medium .may vbe drawn oii'through the outlet pipe 13. In case steam is circulated, a condensationdrawoif line 14 controlled by the valve 15 is tapped mto the bottom ofthe jacket.

The purpose of circulating the heating or cooling medium about thecondensate is to maintain the emulsion which is produced therein, at thedesired temperature, as it isa well known fact that` the temperature atwhich the substances are maintamed during emulsiiication, is a Vitalfactor in the production of a satisfactory combination foremulsiiication of the' substance "introducedthereto.

'f The bitumen, pitch or adhesive binder substance to beemulsiiied isintroduced through the line 16 controlled by the valve 17 while thewater vehicle containing the colloidal .4 emulsifying agent is chargedthrough the pipe 18 regulated by the, valve 19 into an annular space 20surrounding the upper part of the container and occupying the jacketedportion near the upper edge of the container. This space 20 is separatedfrom the jacket by a partition shown at 21. p Y' In the inner walls ofthis annular space are narrow slits shown-at 22, through which theemulsifying liquid ows in a thinnar-v'.

row film running down the edge of the container, and onto the surface ofthe rising emulsion body in a film-like form, evenly distributing itselfover the surface of the emulsion body.

By distributing the mixture of waterland colloidal emulsifying agentinthis mahne'r over the surface of the emulsion body, a betterdistribution .is effected, and a more perfect distribution results.

To the inner jacketedv portion.5 of lthe i open ended cylinder 5 may-beintroduced'a dium throughI the line 23, thereby giving the heating orco'oln body of the emulsion.

steam heating medium or watercooling mef -l'l0 effect aS desired, intheThe medium used, isdrawn 0E through the line 24. The bottom`of thecontainer has a cleanout or emptyin plug 25, and at 26 is an emulsiondrawoi line which is controlled by a gate valve 27.

In carrying out commercially the invention described in Letters PatentNo. 1,302,- 810 issued May 8th, 1919, and as supplemented by subsequentapplications and particularly an app ication Serial No. 274,497, filedFebruary 1st, `1919, it has been the practice to produce a non-adhesiveemulsion Iy dispersing adhesive bituminous binders with an emulsifyingagent such as colloidal clay in an aqueous vehicle.

The bituminous material is, lof course, in the dispersed phase While thewater constitutes the continuous phase of such emulsion, the colloidalclay particles acting to coat or enclose the dispersed particles ofbituminous binder probably by adsorption 'thereby protecting theparticles vof binder from adhesiveness. Under certain conditions when,for example, large proportions of asphalt were dispersed with smallamounts of clay or when the emulsion, after being made, was subjected toextreme dilution with Water, I have found the insulating or protectingquality of the clay particles` could be eectively increased by the useof a xing agent which caused the clay to cling or cluster moretenaciously about the particles of bituminous material. This function ofthe clay can be readily observed by microscopic examination of theemulsion, particularly with the use of stains such as malachite greenwhich brin the clay particles into effective view. lgnother Words, thethird substance acts as a flocculating agent.

The `formation of free oily particles in the emulsion, which seems totake place to a greater extent upon the hot surface thereof, wasobjectionable when it was desired to r'un the emulsion over a papermachine with fibrous stock or in other manufacturing uses when a maximumdegree of non-adhesiveness was desired. From experimentation, it

has been learned that a slight alkalinity ofA the'clay promotes thisoily condition of the emulsion. Lime in the clay will give like resultsand by adding alkali into the clay during emulsification, the tendencyto produce oily particles is greatly accelerated.

To obviate this' objectionable tendency, I add a third substance, havinga slightly acid reaction, and having the purposes of a flocculatingagent, to the einulsifying agent in its aqueous vehicle. Suchsuhstancesv as aluminum sulphate, sodium acid phosphate and others of asimilar character supply elements to the emulsion which obviate theyformation of these oily particles upon the surface of the emulsionduring the mixing and, in addition, tend to cause theI particles ofemulsifying agent to cluster around the adhesive substance dispersedthrough the emulsion as before described. The addition of a thirdsubstance, such as' aluminum sulphate, to an amount of one to fifteenper cent of the emulsifying agent in the emulsion is satisfactorytoproduce these. results. However, it is understood that the quantityand concentration of this third substance is susceptible of variationaccording to its character and lmay be regulated according tothevquality of the emulsifying agent used, and the .character of thebituminous adhesive substance to be emulsied.

In producing this emulsion, the emulsifying agent, which may be clay, isthoroughly mixed in an aqueous vehicle and the third' substance, which,as described, may be aluminum sulphate, sodium acid phosphate ornumerous other materials having a slightly acidI reaction or substancesgiving the above described results and not having the acid reaction, forexample, of calcium chloride is added tothe aqueous suspension. Thissus- `pension is combined with the asphalt in a mixer in which there arelarge paddles kept `constantly revolving Ato thoroughly disperse thebituminous substance through.- the emulsifying liquid. The constructionof this mixer is of importance as one of the essential factors in theformation of the emulsion is that the surface of the emulsion must bekept at all times covered by the emulsifyilig agent which is added.While I am not exactly certain of the causes of this oily formation, itsappearance, when the hot emulsion contacts with air, seems to indicatesome influence of the air in promoting what appears to be a capillaryfractionation of some of the asphaltic particles. It is this keeping ofthe surface of the emulsion constantly covered in connection with thereagent used which reduces the formation of the oil particles duringeniulsiication. Y l

By placing the revolving paddles on a vertical shaft within an inneropeii-ended cylinder and causing a circulation of the emulsion downwardthrough the inner cylinder and upward about the annular space betweenthe inner and outer cylinder and simultaneously with this circulationadding the emulsifying agent in its aqueous vehicle to the loutercircumference of they upper emulsion surface, the emulsifying agent iscompletely covering its surface. During this operation, the emulsion isin the form of a stiff paste and sluggish to accelerate during mixing.It may be mentioned in this regardvthat the third substance added toassist in causing the non-adhesive particles caused to ow inwardly withthe emulsion Y of the emulsifying agent to more firmly.

envelop theadhesive particles of the bituminous substances assists theemulsifyingy 1 agent in 'reducing the Aformation of the oil particles onthe surface of the emulsion, a factor which may be due tothe characterof the material itself, or to the fact that it lgives the emulsifyingagent the tendency to cling to the adhesive particles and, therel fore,more completely protect those exposed on the surface during the initialmixing.

While the effect of the fixing agent is substantially the same whetheradded before or after the formation of the emulsion, if de- I sired toreduce the oily formation, it is preferably addedl with clay and waterprior to emulsification.

I claim as my invention: 71. In an apparatus for forming emulsions, thecombination with an enlar ed mixing chamber, of an open ended sma lercond-uitl t-herein, agitatin elements, :hollow vjackets around the chamer and' conduit adapted to v contain heating or cooling mediums, aclosed annular trough within thev outer jacket, -inlet meanscommunicating with said trough for introducing ingredients to beemulsiied and communications between the. trough and enlarged chamber,Iand withdrawing means for the finished emulsion.'

- 2. In an apparatus for forming emulsions, the combinatlon with anenlarged barrel shaped mixin chamber, of an open ended smallerconduittherein, agitating elements, hollow jackets aroundthe chamber andconduit, adapted to contain heating or cooling mediums, a closed annulartrough within the outer jacket, inlet means communicating with saidtrough ,for introducing emulsifying agents to be emulsified andcommunications between the trough and enlarged chamber, separate inlet.means for introducing the bitumen, and withdrawing means for thefinished emulsion. y

3. In an apparatus for forming emulsions,

the combination with an enlarged mlxing 'I chamber, of an open endedsmaller conduit therein, propelling elements moving in the smallerconduit adapted to cause circulation of the contents downwardly throughthe open ended smaller conduit and then upl LESTER KIRSCHBRAUN.

